1. Field of the Invention
The present invention relates to an electronic device applicable in a so-called wearable terminal that is worn on the body of a user.
2. Description of the Related Art
In recent years, the development and commercial production of wearable terminals which can provide useful information have been actively advanced. While worn on the body during exercise or in daily life, various kinds of biological information and physical information can be acquired. For example, Japanese Patent Application Laid-Open (Kokai) Publication No. 2007-075201 discloses an aerobic exercise retaining device having a wristwatch type appearance which detects cardiac rate and movement speed while mounted on a user's wrist and notifies the user of various kinds of information based on that detected reference data via a notification means or a display section.
Wearable terminals such as this are used by being directly worn on a part of a human body, such as a wrist or an arm. Accordingly, they are desired by the market and users to be thin with light weight and have a shape with a curvature conforming to a part where they are worn. In addition, in health-conscious boom and sport boom in recent years, high design quality and functionality are desired for wearable terminals as well as sportswear, goods, training machines, and the like. For example, Japanese Patent Application Laid-Open (Kokai) Publication No. 2007-078670 discloses a portable device having an outer appearance of a thin stylish wristband type, which provides various information such as a time and timing information via a display panel provided by being curved conforming to a wrist or an arm where the device is worn.
In a wristband-type wearable terminal such as this, in order to achieve an outer shape having a curvature conforming to a part where it is worn, various electronic components and structural members incorporated therein are required to be thin and have a curved structure or a structure corresponding to a curve. Also, along with an increase in the functionality of the wearable terminal, various electronic components and the like are required to be incorporated.
However, this electronic device having a thin curved shape has following problems. For example, by the use of a flexible printed circuit board (FPC), an inner structure conforming to a curved shape can be achieved so as to actualize an electronic device having a thin curved shape. However, it is difficult to ensure strength that can be resistant to force externally applied at the time of manufacturing or using the electronic device.
In order to solve this problem, the rigidity of an exterior member thereof is increased in one method, and a reinforcing member is provided inside thereof in another method. However, in cases where components and members constituting an electronic device are assembled to have a curved shape with a specific curvature, the peripheral lengths of components arranged overlapping with or adjacent to each other may be subtly changed, or variation at the time of manufacture of the components and members and work variation when the components and members are assembled at the time of manufacturing an electronic device may occur, whereby components, a component and a member, or members easily come contact with each other.
Also, the electronic device in a thin curved shape has another problem in that contact due to a dimensional difference occurring from warpage or deformation by external forces is difficult to be avoided. Due to these variations or the occurrence of a dimensional difference, damage, exfoliation, and the like of a component or member may occur, which may significantly affect the product quality.
The present invention has been conceived in light of the above-described problems. An object of the present invention is to provide an electronic device whose product quality is favorable even if manufacture variation, work variation at the time of assembling, or a dimensional difference due to warpage or deformation occurs to a component or member that is mounted in a device having a thin curved shape.